Fungi are used in many industrial processes, such as the production of enzymes, vitamins, polysaccharides, polyhydric alcohols, pigments, lipids, and glycolipids. Some of these products are produced commercially while others are potentially valuable in biotechnology. Fungal secondary metabolites are extremely important to our health and nutrition and have tremendous economic impact. In addition to the multiple reaction sequences of fermentations, fungi are extremely useful in carrying out biotransformation processes. These are becoming essential to the fine-chemical industry in the production of single-isomer intermediates. Recombinant DNA technology, which includes yeasts and other fungi as hosts, has markedly increased markets for microbial enzymes. Molecular manipulations have been added to mutational techniques as a means of increasing titers and yields of microbial processes and in the discovery of new drugs. Today, fungal biology is a major participant in global industry. Moreover, the best is yet to come as genomes of additional species are sequenced at some level (cDNA, complete genomes, expressed sequence tags) and gene and protein arrays become available.